Node.js) 백준 1662번: 압축

https://www.acmicpc.net/problem/1662

1662번: 압축

 

 

const input = require('fs').readFileSync('./dev/stdin').toString().trim();
class Node {
	constructor(item) {
		this.item = item;
		this.prev = null;
	}
}

class Stack {
	constructor() {
		this.top = null;
		this.size = 0;
	}

	push(item) {
		const node = new Node(item);
		node.prev = this.top;
		this.top = node;
		this.size += 1;
	}

	pop() {
		const popItem = this.top;
		this.top = this.top.prev;
		this.size -= 1;
		return popItem.item;
	}
}

const stack = new Stack();
for (let i = 0; i < input.length; i++) {
	if (stack.length == 0) {
		stack.push(input[i]);
	} else {
		const c = input[i];
		switch (c) {
			case ')':
				let x = 0;
				while (stack.top.item != '(') {
					const item = stack.pop();
					if (typeof item === 'string') {
						x += 1;
					} else {
						x += item;
					}
				}

				stack.pop();
				const n = +stack.pop();
				stack.push(x * n);
				break;
			default:
				stack.push(c);
				break;
		}
	}
}
let answer = 0;
while (stack.size > 0) {
	const item = stack.pop();
	if (typeof item === 'string') {
		answer += 1;
	} else {
		answer += item;
	}
}
console.log(answer);